Ozzie, as he was nicknamed, had to be put to sleep on the advice of vets.
The cat was reported to Cats Protection Armagh Branch after being found scavenging for food in a garden last month.
Volunteers were surprised when a routine scan revealed he had a microchip registered in Sydney, and spent weeks unravelling his past.
Gillian McMullen, co-ordinator of the branch, said Ozzie’s Australian owners were traced and explained his past.
“It turns out he was originally called Tigger and had come to the UK with a pet passport along with his family on their travels. Somehow he had become separated from them – we’re not sure how – and had ended up being homed to a new family in the Co Armagh area,” she said.
“It seems he had managed to get lost and that’s when we found him as a stray. He was a lovely cat, very wise and so very affectionate.”
She said the case highlights the importance of keeping microchip details up to date so you can be reunited with your pet.